topic Performance issues with a very large expression in QlikView

Performance issues with a very large expression

Mon, 26 Sep 2011 16:18:53 GMT

Dear friens

I need Help

I have a expression that is X = Sales - Cost - Ga-Gb-Gc-Gd each party (Sales - Cost - Ga-Gb-Gc-Gd) is a large expression containing different Sum() with set analysis conditions and aggregates . I have performance problems (CPU Performance) when calculating the formula. The QV Server has 16GB and Xeon Processor.

Can anyone suggest a technique to develop this, I try the pre-calculate from the load statement Ga, Gb, Gc and Gd but would lose the detail of each of these concepts and in other reports necessary to show individual Ga, Gb, Gc and Gd

Performance issues with a very large expression

Mon, 26 Sep 2011 16:42:25 GMT

Hi marcosengineerQV,

I would suggest to do the calculation in the load script level. Use this expression to create a new field in your fact table.

BTW, what is the data volume(number of records) and data size.

Hope this helps,

Bikash

Performance issues with a very large expression

jonathandienst — Mon, 26 Sep 2011 17:38:30 GMT

The performance of the expression is also affected by the structure of your data model. If, in the expression, you are using fields from many tables, especially if the association goes through too many levels, the performace will suffer.

You can reduce the number of tables in your loadscript by mapping attributes into the fact table and denormalising others and your expression performance may improve.

Regards

Jonathan